Why should we be opposed to same-sex marriage as long as we don’t permit it in our churches?
We already have clear biblical reasons for not allowing same-sex marriage in our churches. But what about out in the public square, where we cannot argue from the Bible? Does gay marriage affect our own marriages?
There actually are good reasons–using rational arguments apart from the Bible–for opposing same-sex marriage in society as a whole.
In short, gay marriage is not for the public good. It is not good for children. The best social science has shown us repeatedly that, all other things being equal, children need both a mother and a father for human flourishing. Gay marriage deprives children of having those two different kinds of influence—mothering and fathering.
Besides, the law has teaching value. When the government officially endorses gay marriage, it says children do not need both a mother and father for human flourishing. It departs from the common consensus of nearly every culture in the last three millennia that marriage is about procreation primarily and that children do best when raised by both a mother and father.
It also reinforces the idea that marriage is only an emotional union—which will increase marital instability because emotions are fickle.
Finally, gay marriage opens the door to polygamy and polyamory (marriage of three or more). There are people favoring both of these kinds of unions waiting to be accepted and protected by law. If gay marriage is protected, polygamy and polyamory will be protected as well. There is no philosophical or legal way to stop either, once marriage is redefined as based on love alone and not designed to raise children—which is how acceptance of gay marriage will indeed redefine marriage.
So government recognition of gay marriage may not affect our marriages immediately or directly, but over the course of time will lead people to think that marriage has nothing intrinsically to do with children, and that children do not need mothering and fathering both. Government recognition will also suggest strongly that marriage is about feelings and not the nurture of the next generation. Children and society both will suffer from these changed understandings.